Field of the Invention
This invention relates to improved flow seats for poppet valve assemblies, and particularly to flow seats having port exit constructions exhibiting reduced flow losses.
Description of the Prior Art
Valve assemblies using poppets movable alternately, into, and out of, engagement with the exit of a fluid port for controlling fluid flow are well known in the art. See e.g. U.S. Pat. No. 4,228,820. Examples of the use of such poppet valve assemblies are in gas compressors where, in larger models, the poppet valve assembly can include a number of separate poppet valves operating in parallel in the same valve assembly.
As in other types of check valves, poppet valve assemblies can introduce unwanted, unrecoverable pressure drops along the fluid path which can result in undesireable flow throttling and reduce compressor overall efficiency. These unrecoverable pressure drops stem not only from the frictional losses in the component but also from the form losses caused by abrupt expansions or contractions in the component cross-sectional flow area. Eddy formations and other hydrodynamic processes at these flow area changes can result in the unwanted conversion of kinetic energy of the flowing fluid to heat energy which cannot be recovered as PV energy in a diffuser and thus represent a loss in compressor efficiency.
It is a fundamental object of the present invention to reduce the energy losses at the port exit region of the flow seat. Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.